1. Field of Invention
This invention relates to a ball valve for refrigerating system.
2. Description of the Related Art
It is known to use ball valves for connecting, intercepting or regulating a cold medium in split refrigerating systems. Generally ball valves (see FIG. 1) have PTFE plastic sealing gaskets on both sides of the valve ball. By screwing in the valve seat along the thread on one side of the valve body, under certain compression, the interactive valve ball and sealing gaskets within the valve body cling to each other closely, and thus function as seal. A valve rod with an “O” ring is connected to the valve ball, so as to open or close the ball valve conveniently by turning the valve rod which drives the valve ball turn. However, due to obvious compression creep of the PTFE plastic sealing gaskets, this kind of ball valve suffers from great permanent compression deformation under high temperature and pressure, thus causing the decreasing of sealing impacting force between the interactive valve ball and PTFE plastic sealing gaskets. The sealing effect is not ideal.